Polyether polyols modified with epoxy resin-diamine adducts

ABSTRACT

Polyether polyols modified with adducts of epoxy resins, such as the diglycidyl ether of Bisphenol A, and diamines, such as polyoxypropylenediamine, are described. The resulting modified polyether polyols have a molecular weight of from about 2,000 to 7,000 and are useful in the preparation of flexible polyurethane foams. The mole ratio of epoxy equivalents to amine equivalents in the adduct ranges from about 2/1 to 10/1.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to U.S. patent application Ser. No. 619,434,filed of even date herewith, which is concerned with the production offlexible polyurethane foams made using polyether polyols modified withepoxy resin-diamine adducts.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the modification of polyether polyols and moreparticularly relates to the modification of polyether polyols with epoxyresin-diamine adducts.

2. Description of the Prior Art

Presently, polyether polyols suitable for use in flexible foams are madeby the reaction of glycerine with mixtures of alkylene oxides. Personsskilled in the art of making polyols can add alkylene oxides topolyhydric initiators such as glycerine or to an intermediate molecularweight alkylene oxide adduct of the initiator to prepare products in the20-60 hydroxyl number range. While generally satisfactory, foamsprepared from these prior art polyols are not firm enough for manycushioning applications particulary at lower foam densities.Conventional means of producing firmer (higher ILD) foams such as higherfunctionality initiators, short chain crosslinkers or fillers lead toother deficiencies in foam properties such as closed cells, poor tearand elongation properties and increased foam density. It is, therefore,an object of this invention to increase the functionality of triols bytheir reaction with epoxy resins-diamine adducts to prepare a new typeof polyether polyol which would produce useful flexible foams. Thepolyols of this invention would also be expected to find application insemiflexible foams and reaction injection molded elastomers.

Other patents disclose reactions involving polyols and epoxy resins.Japanese Pat. No. 71-24,255 concerns the reaction of a glycerine-based3,000 molecular weight triol with 2% bisphenol A epoxy resin to producefoams with increased hardness. A close examination of this patent willshow that the epoxy resin is added at only the end of the triol chain.

U.S. Pat. No. 3,012,984 describes how hydroxyl terminated polyesters,epoxy resins and isocyanate terminated prepolymers may be reacted in aninert organic solvent to produce metal primers and coatings. U.S. Pat.No. 3,010,940 discloses how phenol, epoxy resins, polyisocyanates andalphamethylbenzyldimethylamine react to produce various polyurethanecoatings. U.S. Pat. No. 3,448,046 describes how polyols containingchlorine are mixed with epoxy resins before reaction with an isocyanate.The free epoxides scavenge the HCl in the polyol and do not contributeto the functionality of the polyol. The reaction of an epoxide with analcoholic hydroxyl group is set out in U.S. Pat. No. 3,317,609. Further,British Pat. No. 968,102 describes how polyols suitable for polyurethanefoams may be prepared from the reaction of a polyol, and an epoxy resinin the presence of an acidic catalyst.

Further prior art polyols include those described in GermanOffenlegungschrifft No. 2,056,080. This patent describes how epoxyadhesives may be made by the reaction of epoxy resins with4-mercaptobutanol-blocked urethane prepolymers which are made fromtoluene diisocyanate and various polyols. German Offenlegungschrifft No.1,905,696 discloses how polyurethane lattices may be produced bychainextending a urethane prepolymer by using the reaction product ofpolyethylene glycols of a molecular weight of about 5,000 to 10,000, andan aromatic diglycidyl ether. The modification of epoxy resins byheating them with added polyalkoxylated disaccharides is described inBelgium Pat. No. 785,020.

It is known to modify polyether polyols with epoxy resins alone. Forexample, U.S. Pat. No. 4,316,991 to Texaco Inc. teaches that polyolsmodified with epoxy resins of 2,000 to 7,000 molecular weight produceflexible polyurethane foams with higher load bearing properties thanunmodified polyols. U.S. Pat. No. 4,309,532, also to Texaco Inc.,reveals the modification of rigid amino polyols by their reaction withepoxy resins and alkylene oxides.

Other patents disclosing polyethers and polyether polyols from alkyleneoxides and compounds having more than one epoxy group include U.S. Pat.Nos. 2,792,354; 3,544,655; 4,113,785 and 4,230,827.

SUMMARY OF THE INVENTION

The invention concerns a modified polyether polyol produced by adding anepoxy resin-diamine adduct to a polyether polyol during the reaction ofan alkylene oxide with a polyol initiator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The modified polyether polyols of the invention may be made by adding anepoxy resin-diamine adduct to a polyether polyol any time during thereaction of one or more alkylene oxides with a polyol initiator. Thus,the epoxy resin-diamine adduct may be placed in the middle, near theends or at the ends of the resultant polyether polyol molecules.Preferably, the epoxy resin-diamine adduct is situated in the middle ofthe final polyol molecule. It should be noted that, like most polymerproducts, the final modified polyether polyol is actually a distributionof highly similar, slightly different molecules.

The epoxy resin-diamine adducts suitable for the method of thisinvention may be made simply by heating suitable epoxy resins anddiamines together at a temperature in the range of about 25° to 100° C.

It is anticipated that a wide variety of epoxy resins would be useful inpracticing this invention. The vicinal polyepoxide containingcompositions are organic materials having an average of at least 1.8reactive 1,2-epoxy groups per molecule. These polyepoxide materials canbe monomeric or polymeric, saturated or unsaturated, aliphatic,cycloaliphatic, aromatic or heterocyclic, and may be substituted ifdesired with other substituents besides the epoxy groups; e.g., hydroxylgroups, ether radicals, aromatic halogen atoms and the like.

Preferred polyepoxides are those of glycidyl ethers prepared byepoxidizing the corresponding allyl ethers or reacting, by knownprocedures, a molar excess of epichlorohydrin and an aromaticpolyhydroxy compound; i.e., isopropylidene bisphenol, novolak,resorcinol, etc. The epoxy derivatives of methylene or isopropylidenebisphenols are especially preferred. The diglycidyl ether of Bisphenol Ais used in the examples herein. Some of these epoxy resins are known inthe trade as EPON® resins and may be obtained from Shell Chemical Co.

A widely used class of polyepoxides which are useful according to theinstant invention includes the resinous epoxy polyethers obtained byreacting an epihalohydrin, such as epichlorohydrin, and the like, witheither a polyhydric phenol or a polyhydric alcohol. An illustrative, butby no means exhaustive, listing of suitable dihydric phenols includes4,4'-isopropylidene bisphenol, 2,4'-dihydroxydiphenylethylmethane,3,3'-dihydroxydiphenyldiethylmethane,3,4'-dihydroxydiphenylmethylpropylmethane,2,3'-dihydroxydiphenylethylphenylmethane,4,4'-dihydroxydiphenylpropylphenylmethane,4,4'-dihydroxydiphenylbutylphenylmethane,2,2'-dihydroxydiphenylditolylmethane,4,4'-dihydroxydiphenyltolylmethylmethane and the like. Other polyhydricphenols which may also be co-reacted with an epihalohydrin to providethese epoxy polyethers are such compounds as resorcinol, hydroquinone,substituted hydroquinones; e.g., methylhydroquinone, and the like.

Another class of polymeric polyepoxides which can be amine cured and arein accordance with the instant invention includes the epoxy novolakresins obtained by reacting, preferably in the presence of a basiccatalyst; e.g., sodium or potassium hydroxide, an epihalohydrin, such asepichlorohydrin, with the resinous condensate of an aldehyde; e.g.,formaldehyde, and either a monohydric phenol; e.g., phenol itself, or apolyhydric phenol. Further details concerning the nature and prepartionof these epoxy novolak resins can be obtained in Lee, H. and Neville,K., Handbook of Epoxy Resins, McGraw Hill Book Co., New York, 1967.

It will be appreciated by those skilled in the art that the polyepoxidecompositions which are useful according to the practice of the presentinvention are not limited to those containing the above describedpolyepoxides, but that these polyepoxides are to be considered merely asbeing representative of the class of polyepoxides as a whole.Particularly preferred are aliphatic epoxides, the diglycidyl ether ofBisphenol A and epoxy novolak resins.

The diamines useful in the method of this invention includealkylenediamines containing 2 to 6 carbon atoms such as ethylenediamine,1,2-diaminopropane, 1,3-diaminobutane, 1,5-diaminopentane,1,6-diaminohexane and the like, aromatic diamines such as m-, o- andp-phenylenediamine, and polyoxyalkylenediamines in the 200 to 2,000molecular weight range. Polyoxyalkylenediamines are particularlypreferred in the method of this invention, in particularly theJEFFAMINE® polyoxypropylenediamines sold by Texaco Chemical Company. Itis contemplated that other alkoxylated amines would be useful in themethod of this invention such as polyoxyethylenediamines andpolyoxybutylenediamines.

When making the epoxy resin-diamine adduct it is preferred that the moleequivalents of epoxy in the polyepoxide to mole equivalents of amine inthe diamine be in the range of about 2/1 to 10/1.

It is well known that polyethers for polyurethane applications can beprepared by the base catalyzed reaction of propylene oxide with aninitiator having a low hydrogen functionality; that is, containing fromthree to four reactive hydrogen atoms. Such initiators include, forexample, glycerine, trimethylolpropane, 1,2,6-hexanetriol,pentaerythritol, triethanolamine, ethylenediamine andaminoethylpiperazine. Other initiators include such compounds asethylene glycol, propylene glycols, butylene glycols, pentane diols,bis(4-hydroxycyclohexyl)dimethylmethane, 1,4-dimethylolbenzene,glycerol, 1,2,6-hexanetriol, trimethylolpropane, mannitol, sorbitol,erythritol, pentaerythritol, their dimers, trimers and higher polymers;e.g., polyethylene glycols, polypropylene glycols, triglycerol,dipentaerythritol and the like, polyallyl alcohol, polyhydricthioethers, such as 2,2'-,3,3'-tetrahydroxydipropylsulfide and the like,mercapto alcohols such as monothioglycerol, dithioglycerol, and thelike, polyhydric alcohol partial esters, such as monostearin,pentaerythritol monoacetate, and the like, and halogenated polyhydricalcohols such as the monochlorohydrins of glycerol, sorbitol,pentaerythritol and the like. If base catalysis is used, the alkalinecatalysts normally employed are sodium hydroxide and potassiumhydroxide. Other techniques to prepare polyols are known to thoseskilled in the art.

Polyether polyols having equivalent weights of up to about 750 arenormally prepared in a one-step process by the reaction of propyleneoxide with such an initiator. For the preparation of larger molecules, atwo-step process is usually employed. In the first step, a producthaving an equivalent weight of from about 150 to about 750 is prepared,and in the second step this is reacted further with propylene oxide toprepare the higher molecular weight product.

In the method of this invention, the epoxy resin-diamine adduct may beadded at any stage of the polyether polyol formation. In other words,the epoxy resin-diamine adduct may be added to the initiator before theaddition of any alkylene oxide, during the addition of an alkylene oxideor after the addition of all the alkylene oxide as a cap. It ispreferred that the epoxy resin-diamine adduct is added into the middleof the polyether polyol; that is, after some alkylene oxide has beenreacted with the initiator but before the alkylene oxide addition iscomplete.

The alkylene oxides useful in this invention are ethylene oxide,propylene oxide and 1,2-butylene oxide. Ethylene oxide and propyleneoxide are preferred for this invention, and these reactants are used inthe examples herein. More than one alkylene oxide may be added to thereaction mixture as deemed necessary by one skilled in the artpracticing this invention. In fact, it is preferred that a mixture ofethylene oxide and propylene oxide be used.

The reaction conditions of temperature and pressure may be selected bythe invention practitioner to meet certain specifications required bythe polyol for a particular use. The examples herein use a pressure ofabout atmospheric to 100 psig and a temperature of about 50° to 150° C.as preferred for making modified polyether polyols that would be usefulin flexible foams.

The amount of epoxy resin-diamine adduct should be such that the finalmodified polyether polyol contains from about 0.5 to 5.0 wt. % of theadduct. The final molecular weight of the modified polyether polyolsshould be on the order of 2,000 to 7,000, and they should have ahydroxyl number of from about 20 to 60.

The modified polyether polyols will be further illustrated by thefollowing examples which will demonstrate the preparation of the epoxyresin-diamine adduct, its incorporation into a polyether polyol and thenthe modified polyol's use in a polyurethane foam. It is well known touse polyols to react with polyisocyanates in the presence of a catalystsuch as a tin or tertiary amine compound and a blowing agent togetherwith various additives. See, for example, U.S. Pat. Nos. 4,338,408;4,342,687 and 4,381,353, incorporated by reference herein.

It has been discovered that the modified polyether polyols of thisinvention are useful in the preparation of flexible polyurethane foamswhich have improved properties over those made from prior art polyols.Flexible foams made from 3,500 molecular weight (average) polyols ofthis invention have equivalent firmness and better elongation propertiesthan foams made from a 3,000 molecular weight unmodified polyol. Sincethe 3,500 molecular weight polyols have a lower polyisocyanaterequirement than the 3,000 molecular weight material, these advantagesare realized with a net saving of isocyanate.

Further, higher levels of the epoxy resin-diamine adduct can beincorporated into the polyols as compared to the epoxy resin alone. Inaddition, there is less chance of gelation using the epoxy resin-diamineadducts of this invention as compared to the use of the epoxy resinalone which results in the formation of lower viscosity polyol products.

EXAMPLE 1

This example will illustrate the preparation of the epoxy resin-diamineadduct of this invention. Into a 2-liter three-necked flask equippedwith a stirrer, thermometer, condenser, and nitrogen source was charged1283 g of diglycidyl ether of Bisphenol A (DGEBPA). The DGEBPA washeated to 65° C. and 64.15 g of a 230 molecular weightpolyoxypropylenediamine (JEFFAMINE® D-230 made by Texaco Chemical Co.)was slowly added. The reaction mixture was then heated at 70°-80° C. for1.0 to 2.0 hours. The product was a highly viscous yellow liquid.

EXAMPLE 2

Into a ten-gallon kettle was charged 5.0 lbs of a 600 molecular weightpropylene oxide (PO)/ethylene oxide (EO) adduct of glycerine(alkalinity, mg KOH/g 25.35). The reactor was then purged withprepurified nitrogen. A mixture of 9.5 lbs of PO and 0.35 lbs of EO wasthen reacted at 104°-110° C. at 50 psig. Approximately 1.3 hours wererequired for addition of the mixed oxides. The reaction mixture was thendigested to an equilibrium pressure. The DGEBPA-diamine adduct ofExample 1 (0.5 lb) mixture was then reacted at 105°-110° C. Anadditional 9.5 lb of PO and 0.35 lb of EO was then reacted at 105°-110°C. over a 1.3 hour period. The reaction was then terminated by reactionwith 0.4 lbs of PO. After digestion to an equilibrium pressure, thealkaline product was neutralized by stirring with 345 g of magnesiumsilicate. Di-t-butyl-p-cresol (46.4 g) and octylated diphenylamine (7.0g) were also added at this point. The neutralized product was thenvacuum stripped to a minimum pressure, nitrogen-stripped one-half hourand filtered. The finished product had the following properties.

    ______________________________________                                        Acid number, mg KOH/g                                                                               0.008                                                   Hydroxyl number, mg KOH/g                                                                          54.5                                                     Water, wt. %          0.01                                                    Unsaturation, meq/g   0.035                                                   pH in 10:6 isopropanol/water                                                                       7.5                                                      Color, Pt-Co          25                                                      Sodium, ppm          0.2                                                      Potassium, ppm       0.2                                                      Peroxides, ppm       0.5                                                      Viscosity, °F., cs                                                     77                   767                                                      100                  368                                                      ______________________________________                                    

EXAMPLES 3-5

This example will further illustrate this invention using various levelsof the DGEBPA-diamine adduct of Example 1. These polyols were preparedusing the general procedure of Example 2. Reaction charges, details ofpreparation, and properties are shown in the following table.

    ______________________________________                                                        3      4        5                                             ______________________________________                                        Charge                                                                        600 m.w. PO/EO adduct of                                                                        10.0     5.0      5.0                                       glycerine, lb.sup.1                                                           PO, lb                    17.4   9.15   9.5                                                 mixed                                                           EO, lb        step 1      2.6    0.35   0.35                                  DGEBPA-diamine adduct of Ex.                                                                    0.5      0.9      1.8                                       1, lb                                                                         PO, lb                    25.0   9.15   9.5                                                 mixed                                                           EO, lb        step 2      3.6    0.35   0.35                                  PO, lb            1.8      0.7      0.4                                       Magnesium silicate, g                                                                           700      350      350                                       Di-t-butyl p-cresol, g                                                                          110.7    464      46.8                                      Octylated diphenylamine, g                                                                      16.6     7.0      7.3                                       Reaction details                                                              DGEBPA-diamine content,                                                                         0.82     3.5      6.69                                      wt. %                                                                         Temperature, °C.                                                                         105-110  105-110  105-110                                   Pressure, psig    50       50       50                                        Oxide addition time, hr                                                                         5.7      4.5      4.5                                       Properties                                                                    Acid number, mg KOH/g                                                                           0.008    0.006    --                                        Hydroxyl no., mg KOH/g                                                                          46.7     54.3     52.0                                      Water, wt. %      0.04     0.04     --                                        Unsaturation, meg/g                                                                             0.021    0.032    --                                        pH in 10:6 isopropanol/water                                                                    8.0      7.5      --                                        Color, Pt-Co      25       30-40    --                                        Sodium, ppm       0.2      0.2      --                                        Potassium, ppm    0.2      0.2      --                                        Peroxide, ppm     1.3      0.74     --                                        Viscosity, °F., cs                                                     77                669      1142     17864                                     100               348      555      2156                                      ______________________________________                                         .sup.1 Alkalinity, mg KOH/g = 25.75   PG,14                              

EXAMPLES 6-13

These examples will demonstrate that higher levels of the DGEBPA-diamineadduct of Example 1 can be incorporated into polyols than DGEBPA aloneto prepare lower viscosity products. This serves to reduce the chance ofgelation during the reaction.

In these experiments, various levels of the DGEBPA diamine adduct werereacted with an 1815 molecular weight PO/EO adduct of glycerine whichhad an alkalinity of 8.26 mg KOH/g. This corresponds to the mid-point ofPO/EO addition (step 1) as described in Example 2. Viscosities of theresultant products are shown in the following table.

    __________________________________________________________________________    Example No.  6  7  8   9   10 11 12 13                                        __________________________________________________________________________    DGEBPA-diamine adduct                                                                      -- -- --  --  3.85                                                                             5.66                                                                             7.4                                                                              9.1                                       of Ex. 1, wt. %                                                               DGEBPA, wt. %                                                                              3.85                                                                             5.66                                                                             7.4 9.1 -- -- -- --                                        Viscosity, 77° F., cps                                                              2278                                                                             4177                                                                             17846                                                                             Gelled                                                                            1626                                                                             2612                                                                             5090                                                                             22264                                     __________________________________________________________________________

EXAMPLES 14-17

These examples will illustrate the use of 3500 molecular weight polyolof this invention (Example 3) in the preparation of flexible foam. Itwill further show that foams made from this polyol have the samefirmness and improved elongation as compared to those made from a 3000molecular weight prior art polyol (THANOL® F-3016 made by TexacoChemical Co.). This is accomplished using less toluene diisocyanate. Allfoams were processed on a Martin Sweets foam machine. Formulations andfoam properties are shown below.

    ______________________________________                                        Example No.      14      15      16    17                                     ______________________________________                                        Formulation, pbw                                                              Polyol of Ex. 3.sup.1                                                                          100     100     --    --                                     3000 m.w. PO/EO adduct of                                                                      --      --      100   100                                    glycerine.sup.2                                                               Water            4.0     4.0     4.0   4.0                                    DC-5125 silicones.sup.3                                                                        0.9     0.9     0.9   0.9                                    33% triethylenediamine in                                                                      0.1     0.1     0.1   0.1                                    propylene glycol.sup.4                                                        Dimethylaminoethanol.sup.5                                                                      0.27    0.27    0.27  0.27                                  50% stannous octoate in                                                                         0.27    0.31    0.37  0.47                                  dioctyl phthalate.sup.6                                                       Toluene diisocyanate                                                                           50.54   50.54   52.1  52.1                                   Isocyanate index 1.1     1.1     1.1   1.1                                    Properties                                                                    Density, pcf      1.59    1.58    1.54  1.50                                  IFD (lb/50 in.sup.2)                                                          25%              50.0    51.0    48     49                                    65%              97.0    98.0    91    95.5                                   25R              31.5    31.0    30.0  31.0                                   Tensile, psi     17.6    18.3    17.4  18.2                                   Tear, pli        2.3     2.4     2.7   2.0                                    Elongation, %    135     138     125   127                                    Compression set, 50%                                                                           5.2     5.5     4.2   5.3                                    90%              6.9     7.0     4.3   6.4                                    Ball rebound, %   40      38     39     38                                    Breathability, cfm                                                                             2.1     2.0     3.3   2.1                                    ______________________________________                                         .sup.1 Hydroxyl no., mg KOH/g = 46.7                                          .sup.2 THANOL ® F3016 made by Texaco Chemical Co.                         .sup.3 Silicon surfactant made by DowCorning Corp.                            .sup.4 THANCAT ® TD33 made by Texaco Chemical Co.                         .sup.5 THANCAT DME made by Texaco Chemical Co.                                .sup.6 T10 catalyst made by M & T Chemicals                              

Many modifications may be made by one skilled in the art in the modifiedpolyether polyols of this invention without departing from the spiritand the scope thereof which are defined only in the appended claims. Forexample, it may be found that particular proportions of a certain epoxyresin and a certain diamine reacted under special conditions andincorporated a certain way into a polyether polyol may proveparticularly advantageous.

We claim:
 1. A modified polyether polyol being produced by the processcomprising adding an epoxy resin-diamine adduct to a polyether polyolduring the reaction of an alkylene oxide with a polyol initiator.
 2. Themodified polyether polyol of claim 1 in which the epoxy resin-diamineadduct is from about 0.5 to 5.0 wt. % of the total polyether polyol. 3.The modified polyether polyol of claim 1 in which the addition reactionis conducted at a temperature in the range of about 50° to 150° C. andat a pressure between atmospheric and 100 psig.
 4. The modifiedpolyether polyol of claim 1 in which the modified polyether polyol has amolecular weight in the range of about 2,000 to 7,000 and a hydroxylnumber in the range of about 20 to
 60. 5. The modified polyether polyolof claim 1 in which the alkylene oxide is selected from the groupconsisting of ethylene oxide, propylene oxide, butylene oxide andmixtures thereof.
 6. The modified polyether polyol of claim 1 in whichthe epoxy resin-diamine adduct is made by reacting a diamine from thegroup consisting of polyoxyalkylenediamines having a molecular weight inthe range of about 200 to 2,000, alkylene diamines having 2 to 6 carbonatoms and aromatic diamines, with a polyepoxide from the groupconsisting of aromatic, aliphatic and cycloaliphatic polyepoxides havingan average of at least 1.8 reactive epoxy groups per molecule.
 7. Themodified polyether polyol of claim 6 in which the mole ratio of epoxyequivalents to amine equivalents in the epoxy resin-diamine adduct is inthe range of about 2/1 to about 10/1.
 8. The modified polyether polyolof claim 6 in which the epoxy resin is selected from the group of epoxyresins consisting of aliphatic epoxides, the diglycidyl ether ofBisphenol A and epoxy novolak resins.
 9. A modified polyether polyolbeing produced by the process comprisinga. reacting an epoxy resin witha diamine such that the mole ratio of epoxy equivalents to amineequivalents is in the range of about 2/1 to about 10/1 to form an epoxyresin-diamine adduct, b. reacting an alkylene oxide with a polyolinitiator to form an intermediate alkoxy adduct, c. reacting the epoxyresin-diamine adduct from step a. with the intermediate alkoxy adduct ofstep b. to form an intermediate modified polyol, and d. reacting analkylene oxide with the intermediate modified polyol of step c. to formthe finished modified polyether polyol which contains from about 0.5 to5.0 wt. % epoxy resin-diamine adduct based on the total modifiedpolyether polyol.
 10. The modified polyether polyol of claim 9 in whichall of the reactions are conducted at a temperature in the range ofabout 50° to 150° C. and at a pressure between atmospheric and 100 psig.11. The modified polyether polyol of claim 9 in which the finishedmodified polyether polyol has a molecular weight in the range of about2,000 to 7,000 and a hydroxyl number in the range of about 20 to
 60. 12.The modified polyether polyol of claim 9 in which the alkylene oxide isselected from the group consisting of ethylene oxide, propylene oxide,butylene oxide and mixtures thereof.
 13. The modified polyether polyolof claim 9 in which the diamine is selected from the group consisting ofpolyoxyalkylenediamines having a molecular weight in the range of about200 to 2,000, alkylenediamines having 2 to 6 carbon atoms and aromaticdiamines, and where the epoxy resin is selected from the groupconsisting of aromatic, aliphatic and cycloaliphatic polyepoxides havingan average of at least 1.8 reactive epoxy groups per molecule.
 14. Amethod for modifying polyether polyols comprisinga. reacting an epoxyresin with a diamine to form an epoxy resin-diamine adduct, and b.reacting the epoxy resin-diamine adduct from step a. with a reactionmixture of a polyol initiator with an alkylene oxide to form a modifiedpolyether polyol.
 15. The method of claim 14 in which the modifiedpolyether polyol of step b. is subsequently capped with an alkyleneoxide.
 16. The method of claim 14 in which in step a. the mole ratio ofepoxy equivalents to amine equivalents is in the range of about 2/1 toabout 10/1.
 17. The method of claim 14 in which the modified polyetherpolyol contains from about 0.5 to 5.0 wt. % epoxy resin-diamine adductbased on the total modified polyether polyol.
 18. The method of claim 14in which all of the steps are conducted at a temperature in the range ofabout 50° to 150° C. and at a pressure between atmospheric and 100 psig.19. The method of claim 14 in which the modified polyether polyol has amolecular weight in the range of about 2,000 to 7,000 and a hydroxylnumber in the range of about 20 to
 60. 20. The method of claim 14 inwhich the diamine is selected from the group consisting ofpolyoxyalkylene diamines having a molecular weight in the range of about200 to 2,000, alkylenediamines having 2 to 6 carbon atoms and aromaticdiamines, and where the epoxy resin is selected from the groupconsisting of aromatic, aliphatic and cycloaliphatic polyepoxides havingan average of at least 1.8 reactive epoxy groups per molecule.